Planning application
25/08734/FULL
8 - 9 William Street London SW1X 9HL
Proposal
Installation of air conditioning plant and acoustic enclosure to the rear lower ground courtyard. Alterations to the rear lower ground floor elevation.
As published by the council, reference 25/08734/FULL
Timeline
Dates from the published record
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1 Dec 2025
Received by Westminster
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26 Mar 2026
Decision issued: Application Permitted
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1 Aug 2026
Added to PlanIndex
What a grant of permission means
The process from here
Permission has been granted, usually subject to conditions listed on the decision notice, some of which must be discharged before work starts. The decision notice on the council portal sets out exactly what was approved.
Work must normally begin within three years of the decision or the permission lapses. Neighbours cannot appeal a grant; challenging one means judicial review of how the decision was made, within tight time limits.
About full applications applications
How this application type works
A full application seeks permission for a complete, detailed proposal in one go: siting, design, access and landscaping are all fixed at this stage. It is the standard route for new buildings, conversions and changes of use. The statutory target is eight weeks for smaller schemes and thirteen weeks for major development, though complex cases often take longer by agreement.
Nearby applications
Within 500 metres
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25/08735/LBC Granted
8 - 9 William Street London SW1X 9HL
Installation of air-conditioning plant and acoustic enclosure to the rear lower ground courtyard. Alterations to the rear lower ground floor elevation.
-
26/00188/TCH Awaiting decision
8 - 9 William Street London SW1X 9HL
Use of an area of pavement (part public highway and part private forecourt) measuring 3.44 m x 12.68 m for the placing of 8 tables, 24 chairs, 8 planters and a waiter station in connection with the existing ground floor restaurant.
-
26/02237/FULL Awaiting decision
11 - 12 William Street London SW1X 9HL
Minor internal works to lower floors and installation of part external goods lift. [Linked to 26/02238/LBC]
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26/02238/LBC Awaiting decision
11 - 12 William Street London SW1X 9HL
Minor internal works to lower floors and installation of part external goods lift. [Linked to 26/02237/FULL]
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26/02627/ADV Awaiting decision
8 - 9 William Street London SW1X 9HL
Display of internally illuminated fascia sign measuring 0.833m X 0.31m and 0.833m X 0.31m
-
25/05581/LBC Awaiting decision
81 Knightsbridge London SW1X 7RB
Alterations to shopfront, new signage and internal alterations at ground and basement levels (Linked 25/07100/NMA and 25/07101/ADV).
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26/04989/FULL Awaiting decision
1 Kildare Terrace London W2 5JT
Erection of a mansard roof extending over the main house and side wing, replacement lower ground rear extension with roof terrace above, lowering of lower ground floor slab, installation of an air source heat pump in rear garden, new front boundary treatment, and new second floor window on the north elevation.
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26/04986/FULL Awaiting decision
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Replacement of combustible materials in the render facades; timber decking and plastic soffits/ fascias to terraces with non-combustible materials on the 5th and 6th floors.